World War II Database

1. Chuck says:
1 Aug 2013 03:13:52 AM

I was watching a very good movie called "PT 109". At the end JFK. Was assigned a "new/old" boat, PT 59. The Pictures of this boat as it pulls away from the dock shows it as having NO TORPEDO TUBES. It is like the ones in this picture. Why would it be deployed without tubes, And what was that big gun on the bow of that boat? Any help in this matter would be nice. (If it wasn't just Hollywood making a mistake.)

2. Woody says:
29 Nov 2015 12:25:37 AM

With regard to Chuck's post, my understanding is that torpedo tubes required a charge (usually a 5" shell) to launch the torpedo. This created a large flash which gave their position away to the enemy. The 'roll off' torpedo launchers didn't use a charge, they were literally rolled off the side of the ship and the engine propelled the torpedo. So, no it's not a Hollywood mistake.

3.  David Stubblebine says:
29 Nov 2015 12:20:00 PM

To Chuck and Woody:
There were several styles (or classes) of PT Boats deployed and the different versions used different strategies to launch the different types of torpedoes. Some tubes were designed to use steam to propel the torpedoes out and on PT Boats, compressed air was used in place of steam. This system had its problems and tubes using a powder charge were developed but, as Woody points out, the flash was a problem at night when most PT Boat operations took place. All tube designs were built to fire the 21-inch submarine torpedo but with the advent of the 23-inch Mark XIII aerial torpedo, the older tubes could not be used. Since the Mark XIII was designed to be dropped from the air, dropping them over the sides of the PT Boats made more sense than creating a new tube technology. Plus the extra weight of the tubes could be eliminated and more guns installed. All these changes came about at a time when the Japanese were using more barges and fewer cargo/troop ships making torpedoes less effective against them so it was good timing all around. Also, it is a common mistake to believe the Mark XIII torpedoes were rolled off the PT Boats but this would tumble the gyros with bad results. The aerial torpedoes were slid off of rails so that they dropped into the water without being rolled.